System of electrical distribution.



No. 673,9!2. Patented m I4, 1901. B. G. LAMME.

SYSTEM OF ELECTRICAL DISTRIBUTION.

A fimion flied July 14, 1900.

(No Model.)

I/ I R119! 10 4 5 I 6' 7 ,2

WITNESSES I IIII'EIITOR Z3 @ttcfu/ 7 Trail/Er.

'I'Nll nouns ran: 00. mic-m" wummrou. a. c

UNITED STATES BENJAMIN G. LAMME, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TOTHE WESTINGHOUSE ELECTRIC 8.: MANUFACTURING COMPANY SYLVANIA.

, or PENN- SY STEM OF ELECTRICAL DISTRIBUTION.

SPECIFICATION forming part of Letters Patent No. 673,912, dated May 14,1901.

Application filed July 14, 1900.

To all whom it may concern.-

Be it known that I, BENJAMIN G. LAMME, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented new and useful Improvements in Systems ofElectrical Distribution, of which the following is a specification.

My invention relates to systems of elec [O trical distribution,andparticularly to alternating and direct current systems that areutilized for operating independent sets of translating devicesaud are solocated as to be more or less interconnected.

The object of my invention is to provide a means for transferring energyfrom an alternating-current system to a direct-current system, and viceversa, in order to accommodate changes in load on either or both systems20 where they are so located with reference to each other as to permitof such transference of energy. With these ends in view I have devisedthe means shown in the accompanying drawings, in which- Figure l is adiagram of the apparatus and circuits embodying my invention, and Fig. 2is a similar view of a modification.

Referring to Fig. 1, a three-phase generator 1, having a suitableexciter 2, supplies translating devices 3 by means of conductors 4, 5,and 6, and a direct-current generator 7 supplies translating devices 8through conductors 9 and 10, the two generators 1 and 7 being locatedeitherin the same station orsufficiently near, so that the conductors 4,5, and 6 and9 and 10 may be connected together by means of a rotaryconverter 11 and the alternating-current conductors 12 anddirect-current conductors 13. The rotaryconverter field-magnet winding14 is energized by means of an exciter 15, which is here shown as havinga shunt fieldmagnet winding 16, though it may under certain conditionshave either a series winding or both aseries and a shunt winding. Thearmature of the exciter 15 is mechanically driven by a motor 17, whichis in turn electrically driven from the alternating-current side of therotaryconverter, the connection, as shown, being by means of condoctors18, leading from the conductors l2.

Serial No. 231654;. '\l\l0 model It will be seen that by thisarrangement the exciter of the field-magnet winding 14 is drivensubstantially in synchronism with the alternating-current generator 1.

Referring now to Fig. 2, the several elements of the system are the sameas those shown in Fig. 1 except as will be specifically pointed out, andsince the same referencenumerals are employed the description heretoforegiven may be read in connection with this figure and need not,therefore, be repeated. In this modification the exciter 15 for therotary-converter field-magnet winding 14 instead of being driven by aseparate motor, as shown in Fig. 1, is mechanically driven by the rotaryconverter itself, having its armature either mounted on thearmatureshaft of the rotary converter or coupled thereto or connected bymeans of suitable gearing. As shown, the armature-shafts are coupledtogether, so as to run in synchronism.

It will be understood in connection with each of the figures that atwo-phase alternating-current'system may be employed instead of thethree-phase system shown and that the rotary converter or converters mayhave fieldmagnet windings other than or in addition to the separatelyexcited winding shown, if desired. With either ofthe arrangements shownthe rot-aryconverter tends automatically to transfer energy from eithersystem to the other dependent upon the conditions of load and the speed,850., of the prime movers of the two systems.

Assuming, first, that the alternating-current system is overloaded anddrops in its speed or rate of alternations, the rotary converter willalso drop in speed, its, field will be weakened by reason of the drop inspeed of the exciter, and consequently the armature of the rotaryconverter will tend to speed up and pull ahead of thealternating-current system: This is a condition for feeding energy intothe alternating-current system the same as when two alternators areconnected in parallel, so that when one of them pulls ahead of the otherit will supply the greater amount of energy to the circuit.

Assuming now that the direct-current system is overloaded and thatconsequently its voltage falls 01f, the -voltage of the rotary converterwill tend'to remain normal, since its speed is controlled by thealternating-current system, and its field is therefore constant andunafiected by the drop in electromotive force in the direct-currentsystem. If the rotary converter were excited from the direct-currentmains, its field would vary with the direct-current electromotive force,and the automatic action would be accordingly reduced.

If the direct-current system-and the alternating-current system haveinherently-rising electro motive forces with increase of load, theautomatic transfer of energymay not take place in the right direction;bntrwithfalling characteristics the transfer will be such as will tendto assist. the overloaded -machine-..

If the generator of either system is cut out, the rotary converterwillsupply that. system from the other and will tend to give a constantfrequency of alternations when freely feeding from the directfcurrent tothe alternating-current system.

I claim as my invention 1. The combination with an. alternating--current circuit and a direct-current circuit,

eachof. whichsuppliesits own translating de-- vices with energy, of arotary converter electrically connected between the two circuits, 5 anexciter for said converter, and means for driving said excitersubstantially in synchronis-m with the converter;

2. The combination with an alternatingcurrent circuit and adirect-current circuit,, each of which supplies its own translatingdevices with energy, of'a rotary converterelectrically connected betweenthe two circuits,

an exciter for said converter and a mechanical driving connectionbetween thearmature of the exciter and the armature of the con verter.

3. The combination with an alternatingcurrent circuit and adirect-current circuit respectively supplying energy to translating Idevices, ofmeans for transferring energy from one circuit to the otherin accordance with changes in load comprising a rotary converterelectrically connected between the two, circuits and having aseparately-excited fieldmagnet winding, an exciter for said winding andmeans for driving said exciter substantially in synchronism with thealternatingcurrent generator.

In testimony whereof I have hereunto subscribed my name this 9th day ofJuly, 1900.

BENJ. LAMME.

